Lateral surface etching of two-dimensional (2D) nanosheets results in holey 2D nanosheets that have abundant edge atoms. Recent reports on holey graphene showed that holey 2D nanosheets can outperform their intact counterparts in many potential applications such as energy storage, catalysis, sensing, transistors, and molecular transport/separation. From both fundamental and application perspect...

Local curvature, or bending, of a graphene sheet is known to increase the chemical reactivity presenting an opportunity for templated chemical functionalisation. Using first-principles calculations based on density functional theory (DFT), we investigate the reaction barrier reduction for the adsorption of atomic hydrogen at linear bends in graphene. We find a significant barrier lowering (≈15%...

In the last two decades, the mathematical analysis of material transport has received considerable interest in many scientific fields such as ocean dynamics and astrodynamics. In this contribution we focus on the numerical detection and approximation of transport barriers in dynamical systems. Starting from a set-oriented approximation of the dynamics we combine discrete concepts from graph the...

We model the transport of gas through the martian subsurface in order to quantify the timescales of release of a trace gas with a source at depth using a Fickian model of diffusion through a putative martian regolith column. The model is then applied to the case of methane to determine if diffusive transport of gas can explain previous observations of methane in the martian atmosphere. We inves...

Exploring temporal coherence among light transport paths is very important to remove temporally perception-sensitive artifacts in animation rendering. Using the contribution of a light transport path to all frames in an animation as the sampling distribution function allows us to adapt Markov Chain Monte Carlo (MCMC) algorithms to exploit the temporal and spatial coherence among paths in order ...

The atmospheres of weakly-magnetized neutron stars expand hydrostatically and rotate differentially during thermonuclear X-ray bursts. Differential rotation is probably related to the frequency drifts of millisecond burst oscillations exhibited by about a dozen nuclear-powered X-ray pulsars. Here, we analyze the linear stability of this differential rotation with respect to local, axisymmetric,...

Three-dimensional (3D) topological insulator (TI) has been conjectured as an emerging material to replace copper (Cu) as an interconnect material because of the suppression of elastic scattering from doping and charge impurities for carrier transport on TI surface. We, therefore via full real-space simulation, examine the feasibility of using thin 3D-TI (Bi2Se3) wire for the local electrical in...

In many low-dimensional dynamical systems transport coefficients are very irregular, perhaps even fractal functions of control parameters. To analyse this phenomenon we study a dynamical system defined by a piece-wise linear map and investigate the dependence of transport coefficients on the slope of the map. We present analytical arguments, supported by numerical calculations, showing that bot...

The complex mechanisms governing charge migration in DNA oligomers reflect the rich structural and electronic properties of the molecule of life. Controlling the mechanical stability of DNA nanowires in charge transport experiments is a requisite for identifying intrinsic issues responsible for long-range charge transfers. By merging density-functional theory based calculations and model Hamilt...

Quantification of river bedform variability and complexity is important for sediment transport modeling as well as for characterization of river morphology. Alluvial bedforms are shown to exhibit highly nonlinear dynamics across a range of scales, affect local bed roughness, and vary with local hydraulic, hydrologic, and geomorphic properties. This paper examines sediment sorting on the crest a...